<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Captcha
 * @subpackage Adapter
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */

/** @see Zend_Captcha_Base */
require_once 'Zend/Captcha/Base.php';

/**
 * Word-based captcha adapter
 *
 * Generates random word which user should recognise
 *
 * @category   Zend
 * @package    Zend_Captcha
 * @subpackage Adapter
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Word.php 23775 2011-03-01 17:25:24Z ralph $
 */
abstract class Zend_Captcha_Word extends Zend_Captcha_Base {
	/**#@+
	 * @var array Character sets
	 */
	static $V = array ("a", "e", "i", "o", "u", "y" );
	static $VN = array ("a", "e", "i", "o", "u", "y", "2", "3", "4", "5", "6", "7", "8", "9" );
	static $C = array ("b", "c", "d", "f", "g", "h", "j", "k", "m", "n", "p", "q", "r", "s", "t", "u", "v", "w", "x", "z" );
	static $CN = array ("b", "c", "d", "f", "g", "h", "j", "k", "m", "n", "p", "q", "r", "s", "t", "u", "v", "w", "x", "z", "2", "3", "4", "5", "6", "7", "8", "9" );
	/**#@-*/
	
	/**
	 * Random session ID
	 *
	 * @var string
	 */
	protected $_id;
	
	/**
	 * Generated word
	 *
	 * @var string
	 */
	protected $_word;
	
	/**
	 * Session
	 *
	 * @var Zend_Session_Namespace
	 */
	protected $_session;
	
	/**
	 * Class name for sessions
	 *
	 * @var string
	 */
	protected $_sessionClass = 'Zend_Session_Namespace';
	
	/**
	 * Should the numbers be used or only letters
	 *
	 * @var boolean
	 */
	protected $_useNumbers = true;
	
	/**
	 * Should both cases be used or only lowercase
	 *
	 * @var boolean
	 */
	// protected $_useCase = false;
	

	/**
	 * Session lifetime for the captcha data
	 *
	 * @var integer
	 */
	protected $_timeout = 300;
	
	/**
	 * Should generate() keep session or create a new one?
	 *
	 * @var boolean
	 */
	protected $_keepSession = false;
	
	/**#@+
	 * Error codes
	 */
	const MISSING_VALUE = 'missingValue';
	const MISSING_ID = 'missingID';
	const BAD_CAPTCHA = 'badCaptcha';
	/**#@-*/
	
	/**
	 * Error messages
	 * @var array
	 */
	protected $_messageTemplates = array (self::MISSING_VALUE => 'Empty captcha value', self::MISSING_ID => 'Captcha ID field is missing', self::BAD_CAPTCHA => 'Captcha value is wrong' );
	
	/**
	 * Length of the word to generate
	 *
	 * @var integer
	 */
	protected $_wordlen = 8;
	
	/**
	 * Retrieve session class to utilize
	 *
	 * @return string
	 */
	public function getSessionClass() {
		return $this->_sessionClass;
	}
	
	/**
	 * Set session class for persistence
	 *
	 * @param  string $_sessionClass
	 * @return Zend_Captcha_Word
	 */
	public function setSessionClass($_sessionClass) {
		$this->_sessionClass = $_sessionClass;
		return $this;
	}
	
	/**
	 * Retrieve word length to use when genrating captcha
	 *
	 * @return integer
	 */
	public function getWordlen() {
		return $this->_wordlen;
	}
	
	/**
	 * Set word length of captcha
	 *
	 * @param integer $wordlen
	 * @return Zend_Captcha_Word
	 */
	public function setWordlen($wordlen) {
		$this->_wordlen = $wordlen;
		return $this;
	}
	
	/**
	 * Retrieve captcha ID
	 *
	 * @return string
	 */
	public function getId() {
		if (null === $this->_id) {
			$this->_setId ( $this->_generateRandomId () );
		}
		return $this->_id;
	}
	
	/**
	 * Set captcha identifier
	 *
	 * @param string $id
	 * return Zend_Captcha_Word
	 */
	protected function _setId($id) {
		$this->_id = $id;
		return $this;
	}
	
	/**
	 * Set timeout for session token
	 *
	 * @param  int $ttl
	 * @return Zend_Captcha_Word
	 */
	public function setTimeout($ttl) {
		$this->_timeout = ( int ) $ttl;
		return $this;
	}
	
	/**
	 * Get session token timeout
	 *
	 * @return int
	 */
	public function getTimeout() {
		return $this->_timeout;
	}
	
	/**
	 * Sets if session should be preserved on generate()
	 *
	 * @param bool $keepSession Should session be kept on generate()?
	 * @return Zend_Captcha_Word
	 */
	public function setKeepSession($keepSession) {
		$this->_keepSession = $keepSession;
		return $this;
	}
	
	/**
	 * Numbers should be included in the pattern?
	 *
	 * @return bool
	 */
	public function getUseNumbers() {
		return $this->_useNumbers;
	}
	
	/**
	 * Set if numbers should be included in the pattern
	 *
	 * @param bool $_useNumbers numbers should be included in the pattern?
	 * @return Zend_Captcha_Word
	 */
	public function setUseNumbers($_useNumbers) {
		$this->_useNumbers = $_useNumbers;
		return $this;
	}
	
	/**
	 * Get session object
	 *
	 * @return Zend_Session_Namespace
	 */
	public function getSession() {
		if (! isset ( $this->_session ) || (null === $this->_session)) {
			$id = $this->getId ();
			if (! class_exists ( $this->_sessionClass )) {
				require_once 'Zend/Loader.php';
				Zend_Loader::loadClass ( $this->_sessionClass );
			}
			$this->_session = new $this->_sessionClass ( 'Zend_Form_Captcha_' . $id );
			$this->_session->setExpirationHops ( 1, null, true );
			$this->_session->setExpirationSeconds ( $this->getTimeout () );
		}
		return $this->_session;
	}
	
	/**
	 * Set session namespace object
	 *
	 * @param  Zend_Session_Namespace $session
	 * @return Zend_Captcha_Word
	 */
	public function setSession(Zend_Session_Namespace $session) {
		$this->_session = $session;
		if ($session) {
			$this->_keepSession = true;
		}
		return $this;
	}
	
	/**
	 * Get captcha word
	 *
	 * @return string
	 */
	public function getWord() {
		if (empty ( $this->_word )) {
			$session = $this->getSession ();
			$this->_word = $session->word;
		}
		return $this->_word;
	}
	
	/**
	 * Set captcha word
	 *
	 * @param  string $word
	 * @return Zend_Captcha_Word
	 */
	protected function _setWord($word) {
		$session = $this->getSession ();
		$session->word = $word;
		$this->_word = $word;
		return $this;
	}
	
	/**
	 * Generate new random word
	 *
	 * @return string
	 */
	protected function _generateWord() {
		$word = '';
		$wordLen = $this->getWordLen ();
		$vowels = $this->_useNumbers ? self::$VN : self::$V;
		$consonants = $this->_useNumbers ? self::$CN : self::$C;
		
		for($i = 0; $i < $wordLen; $i = $i + 2) {
			// generate word with mix of vowels and consonants
			$consonant = $consonants [array_rand ( $consonants )];
			$vowel = $vowels [array_rand ( $vowels )];
			$word .= $consonant . $vowel;
		}
		
		if (strlen ( $word ) > $wordLen) {
			$word = substr ( $word, 0, $wordLen );
		}
		
		return $word;
	}
	
	/**
	 * Generate new session ID and new word
	 *
	 * @return string session ID
	 */
	public function generate() {
		if (! $this->_keepSession) {
			$this->_session = null;
		}
		$id = $this->_generateRandomId ();
		$this->_setId ( $id );
		$word = $this->_generateWord ();
		$this->_setWord ( $word );
		return $id;
	}
	
	protected function _generateRandomId() {
		return md5 ( mt_rand ( 0, 1000 ) . microtime ( true ) );
	}
	
	/**
	 * Validate the word
	 *
	 * @see    Zend_Validate_Interface::isValid()
	 * @param  mixed $value
	 * @return boolean
	 */
	public function isValid($value, $context = null) {
		if (! is_array ( $value ) && ! is_array ( $context )) {
			$this->_error ( self::MISSING_VALUE );
			return false;
		}
		if (! is_array ( $value ) && is_array ( $context )) {
			$value = $context;
		}
		
		$name = $this->getName ();
		
		if (isset ( $value [$name] )) {
			$value = $value [$name];
		}
		
		if (! isset ( $value ['input'] )) {
			$this->_error ( self::MISSING_VALUE );
			return false;
		}
		$input = strtolower ( $value ['input'] );
		$this->_setValue ( $input );
		
		if (! isset ( $value ['id'] )) {
			$this->_error ( self::MISSING_ID );
			return false;
		}
		
		$this->_id = $value ['id'];
		if ($input !== $this->getWord ()) {
			$this->_error ( self::BAD_CAPTCHA );
			return false;
		}
		
		return true;
	}
	
	/**
	 * Get captcha decorator
	 *
	 * @return string
	 */
	public function getDecorator() {
		return "Captcha_Word";
	}
}
